PROBLEM TO BE SOLVED: To provide a heat pipe which can be laid horizontally, its producing method, and a method for utilizing that heat pipe effectively, e.g. a method for disinfecting soil at a low cost. SOLUTION: A heat source pipe (2) is inserted into a vacuum pipe (1) encapsulating heating medium fluid (F) in close proximity to the inner circumferential surface thereof thus constituting a heat pipe (A). The heat pipe (A) is laid horizontally in soil, an agricultural house, a planting tray, the underfloor section of a house, or the ground such that the heat source pipe (2) is placed on the bottom side of the vacuum pipe (1) thus utilizing the heat pipe for disinfecting soil through heating, heating the agricultural house, the soil in the planting tray, or the floor, or melting snow.
